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    What is Grade 373?

    Johnson Test Papers Grade 373 filter paper has high wet strength and a larger nominal particle retention rating than comparable Büchner filtration papers enabling fast filtering for gravimetric analysis of thick, coarse particles and gelatinous precipitates. It has a mild texture and high apparent density which favour good load capacity. Acid-treated with minimal fibre shredding, even when wet.

    • Large nominal pore size of 12-15 µm
    • Fast filtration speed (10 seconds according to DIN 53137)
    • High purity (0.06% ash maximum)
    • Compatible with Büchner funnel or Hirsch funnel applications

    Johnson Test Papers offers three grades of low ash hardened filter paper for quantitative analysis. All three are designed for use in gravity and vacuum/suction filtration in Büchner and Hirsch funnel applications and can be customized for an exact fit.

    Grade 373 filter paper can sustain fast vacuum or suction filtration in a Büchner or Hirsch funnel.
    • i.e. iron, aluminium, chromium and zirconium hydroxides
    • copper, copper sulfides, cobalt or iron
    • Si-determination in steel and pig iron analysis in acid and alkali solutions.
    • Air and foodstuffs analysis
    • Chloride and phosphorous in cement, coal and coke

    Whatman Cross Reference = No.54
    Speed class Fast
    Thickness (mm) 0.18
    Pore size (μM) 12-15
    Weight (g/m²) 84
    Filtration Speed (sec*) 10
    Burst Strength (Kg/cm²) >0.3
    *According to DIN 53137
    Diameter (mm) Product Code
    mm: 55 Product code: 373055
    mm: 70 Product code: 373070
    mm: 90 Product code: 373090
    mm: 110 Product code: 373110
    mm: 125 Product code: 373125
    mm: 150 Product code: 373150
    mm: 185 Product code: 373185
    mm: 240 Product code: 373240
    mm: 300 Product code: 373300
    mm: 320 Product code: 373300